Arithmetic Grade Four

Lesson One Hundred: The Game of One

That was all a little too easy! Now we will complicate things just a tiny bit by doing the same sort of thing with fractions with unlike denominators. Consider this first example: 

        1         ?          44
      ----   +  ----   =    ----
       11        44          44

    We know that 1/11 + 10/11 equals 1. So, what we have to
    do is find a fraction equivalent to 10/11 that has 44
    in its denominator:

        10        ?
       ----  =  ----
        11       44

    It's easy to figure out that 10/11 is equivalent to 40/44 and
    that's our answer! (Or more precisely, our answer is 40 since
    that's what fits into the slot marked with the question mark.)
Here's another problem for you to think about carefully. 

  Which of the following when added to 1/4 equals 1?

    A. 1/3
    B. 3/6
    C. 6/8
    D. 8/10
  --------

     We know that 1/4 + 3/4 = 1. So, we want to find a fraction
     which is equivalent to 3/4. The only fraction in the list
     of possible answers equivalent to 3/4 is 6/8 and so our
     answer is C.

Now you get to try a few for yourself.

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